THIS PRODUCT HAS ADJUSTABLE VECEL AT THE BACK AND THE STANDARD SIZE IS SUITABLE FOR HEAD SIZE OF 55-57-57 CM. SIZE CHART: 55Cm(XS) - 56Cm(S) - 57Cm(S/M) - 58Cm(M) - 59Cm(L) - 60Cm(L/XL) - 61Cm(XL) How to Take Head Measurement? When you measure your head circumference 1 cm above your eyebrow, the measurement you find is your head measurement. . MAIN FABRIC 100.00% LINEN, INNER FABRIC 70.00% Cotton. 30.00% Polyester . STORAGE RECOMMENDATION Store in a dry and ventilated place. . Thanks to its special component fabric, it is very light and pleasant to wear.